1. Field
The invention relates to environmental visualization and modeling simulation systems, and to environmental impact assessment systems, and particularly to a method and system for generating a 3-D world model for simulated real terrain optimized for a personal computer.
2. Description of Related Art
Environmental systems modeling has proven to be an effective method for both teaching about the natural environment and about environmental processes and for estimating potential environmental and socio-economic impacts of environmental changes introduced by human activities. The creation of such an environmental model typically begins with real-world source data that has been derived by environmental survey and monitoring activities, including U.S. Geological Survey information or a data collected by another mapping agency or university. The modeling activity typically involves setting the initial state of various parameters and stepping the model through computations that relate the parameters to process interactions between environmental components, such as setting the parameter for water level of a lake and relating that water level to a precipitation process that interacts between the atmosphere and the lake whereby the lake water level is increased. Three-dimensional transport of energy, momentum, chemical species and other interactions between various environmental or ecological state properties are relevant and useful to these modeling activities. "Running" an environmental model consists of stepping computationally through a series of process instructions, iteratively if required, where the steps correspond to time intervals and the degree of potential environmental change corresponds to the simulated length of time from start of the simulation to its termination. For instance, in a series of computations that takes the computer fifteen seconds to execute an environmental model might simulate the effects of a river eroding its banks over a one-hundred year period--called a hundred year run. Accordingly, there is a need for a technique that not only provides an exact depiction of the environmental input data, but a technique that will also enable the simulation system to be reconfigured to represent environmental alteration and to permit query of altered environmental conditions after a model run. For education and for assessing potential environmental impact it is useful to be able to visualize the original environmental conditions, changes imposed to initial conditions prior to modeling, and the resultant conditions after competing the model run. Such visualization is assisted by allowing a system user to examine and navigate within a 3-D world model of the environmental region under study.